From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7443C7618F for ; Tue, 16 Jul 2019 17:50:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AEC72145D for ; Tue, 16 Jul 2019 17:50:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388332AbfGPRum (ORCPT ); Tue, 16 Jul 2019 13:50:42 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:43797 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728137AbfGPRum (ORCPT ); Tue, 16 Jul 2019 13:50:42 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04446;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0TX46pWJ_1563299431; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0TX46pWJ_1563299431) by smtp.aliyun-inc.com(127.0.0.1); Wed, 17 Jul 2019 01:50:39 +0800 From: Yang Shi To: catalin.marinas@arm.com, mhocko@suse.com, dvyukov@google.com, rientjes@google.com, willy@infradead.org, cai@lca.pw, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] Revert "kmemleak: allow to coexist with fault injection" Date: Wed, 17 Jul 2019 01:50:31 +0800 Message-Id: <1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When running ltp's oom test with kmemleak enabled, the below warning was triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is passed in: WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50 Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50 ... kmemleak_alloc+0x4e/0xb0 kmem_cache_alloc+0x2a7/0x3e0 ? __kmalloc+0x1d6/0x470 ? ___might_sleep+0x9c/0x170 ? mempool_alloc+0x2b0/0x2b0 mempool_alloc_slab+0x2d/0x40 mempool_alloc+0x118/0x2b0 ? __kasan_check_read+0x11/0x20 ? mempool_resize+0x390/0x390 ? lock_downgrade+0x3c0/0x3c0 bio_alloc_bioset+0x19d/0x350 ? __swap_duplicate+0x161/0x240 ? bvec_alloc+0x1b0/0x1b0 ? do_raw_spin_unlock+0xa8/0x140 ? _raw_spin_unlock+0x27/0x40 get_swap_bio+0x80/0x230 ? __x64_sys_madvise+0x50/0x50 ? end_swap_bio_read+0x310/0x310 ? __kasan_check_read+0x11/0x20 ? check_chain_key+0x24e/0x300 ? bdev_write_page+0x55/0x130 __swap_writepage+0x5ff/0xb20 The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak has __GFP_NOFAIL set all the time due to commit d9570ee3bd1d4f20ce63485f5ef05663866fe6c0 ("kmemleak: allow to coexist with fault injection"). But, it doesn't make any sense to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same time. According to the discussion on the mailing list, the commit should be reverted for short term solution. Catalin Marinas would follow up with a better solution for longer term. The failure rate of kmemleak metadata allocation may increase in some circumstances, but this should be expected side effect. Suggested-by: Catalin Marinas Cc: Michal Hocko Cc: Dmitry Vyukov Cc: David Rientjes Cc: Matthew Wilcox Cc: Qian Cai Signed-off-by: Yang Shi --- mm/kmemleak.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 9dd581d..884a5e3 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -114,7 +114,7 @@ /* GFP bitmask for kmemleak internal allocations */ #define gfp_kmemleak_mask(gfp) (((gfp) & (GFP_KERNEL | GFP_ATOMIC)) | \ __GFP_NORETRY | __GFP_NOMEMALLOC | \ - __GFP_NOWARN | __GFP_NOFAIL) + __GFP_NOWARN) /* scanning area inside a memory block */ struct kmemleak_scan_area { -- 1.8.3.1